It all started with this site that got stuck in the Google Chrome's DNS cache so that any changes to the Windows/System32/drivers/etc/hosts file were ignored. I didn't want to close all Chrome windows (since the DNS cache is application wide in Chrome), so I googled for an answer. And here it was, a simple url that, typed in the Chrome address bar, would allow me to clear the cache: chrome://net-internals#dns.

But there are a lot more cool things there: testing of failed sites, a log of browser network events, control over open connections and so much more. That got me curious on other cool chrome:// URLs and I found some links listing a lot of them.